CN113840565A - Traction Cable Management for Steerable Conduit - Google Patents

Abstract

Translated fromChinese

一种可转向的导管，包括换能器，该换能器被设置于柔性的远端部处，且经由插管被联接到导管的手柄。柔性的远端部由多个关节牵引线缆来控制，该多个牵引线缆从手柄中的关节控制装置延伸到远端部的远的一端处，使得当一个关节牵引线缆被拉动，而相对的关节牵引线缆被松弛时，柔性的远端部沿着被张紧的关节牵引线缆的方向弯曲。为了使随着时间的推移而变化的牵引阻力最小化，同时仍然提供插管的柔性，具有牵引线缆管腔的插件被设置于插管中，以使每个关节牵引线缆彼此隔离，并与将换能器联接到手柄的其他线缆隔离。

A steerable catheter includes a transducer disposed at a flexible distal end and coupled to a handle of the catheter via a cannula. The flexible distal portion is controlled by a plurality of joint traction cables extending from the joint control device in the handle to the distal end of the distal portion such that when one joint traction cable is pulled, the When the opposing joint traction cable is relaxed, the flexible distal portion bends in the direction of the tensioned joint traction cable. To minimize traction resistance over time, while still providing cannula flexibility, inserts with traction cable lumen are placed in the cannula to isolate each joint traction cable from each other, and Isolated from other cables that couple the transducer to the handle.

Description

Traction cable management for steerable catheter

Technical Field

The present invention relates to the field of medical devices, and more particularly to a method and system for managing an articulation pull cable in a steerable catheter or other steerable devices such as endoscopes, gastroscopes, and transesophageal echocardiography (TEE) probes.

Background

Catheters are commonly used to position components within passages within a patient's body to monitor specific biological characteristics, perform surgical procedures, administer medications, and the like. To navigate through the passageway, steerable catheters have been developed with articulating distal portions.

Fig. 1A-1C illustrate an example of a prior artsteerable catheter 100.Catheter 100 includeshandle 110,cannula 120, flexibledistal end 130, andtransducer 170. Thetransducer 170 acquires imaging data by ultrasound. Other devices may be substituted for thetransducer 170, which may receive optical images of the patient's biological features and/or internal passageways, or which may perform tasks such as making incisions, clearing blockages, administering medications, and the like. To perform these actions,handle 110 is coupled to a medical instrument controller (not shown) and to transducer 170 via one ormore transducer cables 150 located withincannula 120. In the example ofultrasound transducer 170 described above,steerable catheter 100 may be an ultrasound probe for use with an ultrasound system, such as a transesophageal echocardiography (TEE) ultrasound probe, a transvaginal ultrasound probe.

Fig. 1B showscatheter 100 in a "neutral" state, in which flexibledistal portion 130 is not bent or twisted.Handle 110 includes ajoint controller 115 coupled to flexibledistal end 130 viajoint pull cables 160a, 160b (collectively joint pull cables 160) that extend throughcannula 120 to flexibledistal end 130.

As shown in the cross-section of fig. 2A, thesearticulation traction cables 160 are fixedly attached toterminations 175 at the transducer end of the flexibledistal end portion 130 and may be selectively tensioned/pulled by thearticulation controller 115.

As shown, thejoint distraction cables 160a, 160b are disposed opposite one another at the outer peripheral region of thetermination 175. This enables two degrees of freedom for adjusting the orientation of the flexibledistal end portion 130. In some embodiments, the flexibledistal portion 130 includes structural details that limit bending of the flexibledistal portion 130 in two opposite directions. When theupper cable 160b is pulled by thejoint controller 115 and thelower cable 160a is correspondingly slackened by therotation 118 of thejoint controller 115, the tension causes the flexibledistal end 130 to twist upward as shown in fig. 1A.Reverse rotation 119 onjoint controller 115 causeslower cable 160a to be pulled andupper cable 160b to be slackened, causing flexibledistal end 130 to twist downward, as shown in FIG. 1C.

Although twojoint distraction cables 160a, 160b are shown, the steerable catheter may include more cables located on the periphery of thetermination portion 175 to provide additional degrees of freedom of movement. Typically, four joint pull cables are provided to provide horizontal and vertical bending of the flexibledistal end 130.

In some embodiments, as shown in fig. 3, apull cable lumen 165 is provided through the flexibledistal end 130 to provide more uniform tension within the flexibledistal end 130 when thejoint pull cable 160 is tensioned/pulled.

To achieve proper articulation steering, flexibledistal end 130 should be more flexible thancannula 120, butcannula 120 must provide sufficient flexibility to minimize patient discomfort ascannula 120 moves within the patient's internal vasculature. Thus, as shown in the cross-section of FIG. 2B, asingle lumen 190 is provided for routing thetransducer cable 150 and thearticulation pull cable 160 so that the flexibility of thecannula 120 may be determined primarily by the size and composition of the material forming thecylindrical cannula 120. Thesingle lumen 190 also facilitates insertion/deployment of thecables 150, 160 within thecannula 120. However, such anon-structural lumen 190 presents problems that affect the reliability and longevity of thesteerable catheter 100, as described in detail below.

Disclosure of Invention

It is an object of the present invention to provide a more robust catheter or similar elongate medical instrument device design by providing a structure for cabling within the cannula of a steerable catheter or (elongate) device without significantly affecting the flexibility of the cannula.

To better address one or more of these concerns, in one embodiment of the invention, the cannula may include a plurality of inserts spaced along the cannula from the handle to the distal end. Each of the plurality of inserts may include a plurality of lumens including one or more transducer cable lumens and a plurality of pull cable lumens, wherein the plurality of lumens isolate each of the transducer cable and the plurality of articulation pull cables from one another.

Drawings

The invention is explained in further detail, by way of example, with reference to the accompanying drawings, in which:

fig. 1A-1C illustrate examples of prior art steerable catheters.

Fig. 2A-2B illustrate exemplary cross-sections of a steerable catheter of the prior art.

Fig. 3 shows an example of a flexible distal portion of a steerable catheter of the prior art.

Figure 4 shows an example of an insert for placement within a cannula.

Figure 5 shows a plurality of inserts positioned within a cannula.

Fig. 6 and 7 show alternative insert constructions.

Figure 8 shows a series of components for insertion into a cannula.

Fig. 9 shows an alternative insert structure.

Throughout the drawings, the same reference numerals indicate similar or corresponding features or functions. The drawings are included for illustrative purposes and are not intended to limit the scope of the present invention.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular architecture, interfaces, techniques, etc., in order to provide a thorough understanding of the present inventive concepts. However, it will be apparent to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. As such, the description is of exemplary embodiments shown in the drawings and is not intended to limit the claimed invention beyond the scope explicitly included in the claims. For purposes of simplicity and clarity, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

It will be appreciated that the embodiments of the invention described below in a catheter for use in a blood vessel are merely exemplary. The scope of the present invention encompasses any steerable device, such as an elongate medical device, including catheters, which are intended to be inserted into vessels, ducts, passages and cavities of the body, and which have steerable distal portions for imaging, medical procedures, implant placement, implant removal, and the like.

Non-limiting examples of other such medical devices that fall within the scope of the present invention are endoscopes, gastroscopes, transvaginal ultrasound probes, and transesophageal echocardiography (TEE) ultrasound probes. In embodiments that include a TEE, thetransducer 170 is of course an ultrasonic transducer. The invention described below for the exemplary catheter can also be readily implemented in these other elongate medical devices, enjoying similar benefits and improvements over prior art arrangements.

As discussed above, prior art catheters are prone to premature failure due to theunstructured lumen 190 of thecannula 120, as shown in FIG. 2B. After repeated use, thecables 150, 160 often become entangled with each other, resulting in increased resistance to tension and relaxation of thejoint traction cable 160. This increase in resistance tends to cause premature failure of thecatheter 100 because one of thejoint distraction cables 160 cannot be pulled or loosened. This increase in resistance may be reduced by wrapping eachjoint traction cable 160 in a protective sleeve that is sized to allow thejoint traction cable 160 to be pulled and slackened, and that is sufficiently rigid to withstand the deformation imposed by the other cables. However, such protective shielding on each articulation pullcable 160 can greatly affect the overall flexibility of thecannula 120.

Fig. 4 illustrates anexemplary insert 400 providing structure within acannula 420. Theexample insert 400 includes atransducer lumen 450 and a plurality ofpull cable lumens 460, wherein one ormore transducer cables 150 pass through thetransducer lumen 450 and a plurality ofsteering cables 160 pass through the plurality ofpull cable lumens 460. As shown, thepull cable lumen 460 is C-shaped and forms an enclosed volume when disposed within thecannula 420.

As in the conventional catheter shown in fig. 1, thetransducer cable 150 is coupled to atransducer 170 located at the flexibledistal end 130 of the catheter and to thehandle 110 for coupling to a medical control device (not shown) within thehandle 110 or outside of thehandle 110. Thearticulation pull cable 160 is fixedly attached to atermination 175 at one end of the distal end of the flexibledistal portion 130 and is coupled with thearticulation control element 115 in thehandle 110. Depending on the configuration of thecontrol element 115, thejoint distraction cables 160 may be fixedly attached to thecontrol element 115 or movably attached to thecontrol element 115, for example, a pair ofjoint distraction cables 160 comprising a continuous cable located on the periphery of a wheel (which is rotated by the control element 115) to apply tension on one of the pair of joint distraction cables and slacken the other joint distraction cable.Cannula 120 is attached to handle 110 and flexibledistal end 130.

Non-limiting examples oftransducers 170 according to the present disclosure are electromechanical transducers, electroacoustic transducers, such as ultrasonic (or ultrasonic) transducers.

Thelumens 450, 460 provide isolation of thejoint distraction cable 160 from thetransducer cable 150, as well as from each other. Thepull cable lumen 460 is sized to allow free travel of thejoint pull cable 160. In embodiments of the present invention, either thejoint distraction cable 160 or thedistraction cable lumen 460, or both, may be coated with a lubricious material that facilitates advancement of the joint distraction cable through the distraction cable lumen. In some embodiments, the insert includes a lubricious material to facilitate insertion of the insert into thecannula 420. In some embodiments, the insert comprises a high temperature resilient material.

While theinsert 400 may extend the entire length of thecannula 420, such a configuration may interfere with the flexibility of thecannula 420. Thus, in an embodiment of the invention, a plurality ofinserts 400 are provided along the length of the cannula, as shown in FIG. 5. To prevent displacement or rotation of each insert, theinserts 400 may be attached to thecannula 420 with heat staking, RF welding, or other attachment techniques.

Fig. 6 and 7 show alternative constructions of theinsert 400. In fig. 6, an enclosedpull cable lumen 460 is provided for eachjoint pull cable 160 to facilitate assembly. In this embodiment, thetransducer cable 150, thearticulation distraction cable 160, and theinsert 400 may be pre-assembled into a string of components that are then surrounded by thecannula 420, as will be described in further detail below.

FIG. 7 shows an exemplary embodiment in which thetransducer cable 150 is embedded in aninsert 400. That is, eachinsert 400 is molded or otherwise formed around thetransducer cable 150 such that thecable 150 is fixedly attached to eachinsert 400. In this embodiment, when each insert is formed, an enclosedtransducer cable lumen 450 is formed by thecable 150.

Fig. 8 shows an example of a string ofcomponents 800 including atransducer cable 150 embedded in each of a plurality ofinserts 400. Also embedded in eachinsert 400 is apull wire 850. Pullwire 850 may be used to pullstring member 800 throughcannula 420 to form the assembly shown in fig. 5.

If theinsert 400 includes a surroundingpull cable lumen 460, as shown in FIG. 6, thejoint pull cables 160 may be strung through thepull cable lumens 460 of thestring member 800. Alternatively, if theinsert 400 includes an openpull cable lumen 460, as shown in fig. 7, thejoint pull cables 160 may be routed into eachpull cable lumen 460 of theinsert 400 as a string of components similar to the string ofcomponents 800 is pulled into thecannula 420.

Fig. 9 shows an example insert configured to capture eachjoint distraction cable 160 as it is laid into thedistraction cable lumen 460. As shown, theinsert 400 includes a slot having anopening 960, theopening 960 being slightly smaller than the diameter of thearticulation distraction cable 160. In this embodiment, theinsert 400 comprises an elastic material that allows the largerjoint distraction cable 160 to be inserted through thesmaller opening 960. Once inserted, thejoint distraction cable 160 is captured by thedistraction cable lumen 460 within the pliable material as it returns to its original state with anopening 960 that is smaller than the diameter of thejoint distraction cable 160.

Fig. 10 illustrates an exemplary flow diagram 1000 for assembling a steering catheter with an articulation traction cable support located within a cannula. Those skilled in the art will recognize that the illustrated order of steps is provided for ease of understanding, and that the steps may be performed in a different order, and/or that some steps may be performed simultaneously. Those skilled in the art will also recognize that, in addition to installing an insert with an articulation pull cable lumen and a transducer cable lumen in the cannula, assembly of the steering catheter is consistent with known prior art that need not be described in detail in this specification.

At 1010, a plurality of inserts having pull cable lumens are obtained. These inserts may be pre-formed inserts or formed by extrusion or molding around the puller wire and/or transducer cable. At 1015, a pull wire is attached to each insert, and at 1020, one or more transducer cables are routed through each insert. As described above,steps 1010, 1015, and 1020 may be performed simultaneously, such as when the insert is co-extruded over the pull wires and transducer cable.

At 1025, joint distraction cables are routed through the distraction cable lumens of each insert. If the pull cable lumen is a slot, the joint pull cable may be temporarily held in place until the inserter is ready to be pulled into the cannula.

At 1030, the pull wire is passed through the cannula, and at 1035, the pull wire is pulled to pull the assembly of the insert, the transducer cable, and the articulation pull cable into the cannula. In alternative embodiments, the cannula may be extruded or otherwise formed on the assembly, thereby eliminating the need for a pull wire.

At 1040, the insert is attached to the cannula. Such attachment is optional; if the insert is sufficiently held in place by elastic pressure from the wall of the cannula, or by formation of the cannula, at assembly, further attachment may not be necessary. As noted above, heat staking, RF welding, or other attachment techniques may be used if attachment is necessary. In some embodiments, the cannula may be a heat shrink material that facilitates placement of the assembly in the cannula followed by application of heat to attach the cannula to each insert.

At 1045, a transducer cable is attached at each end to couple the transducer to the handle, and at 1050, a joint pull cable is attached at each end of the assembly to couple the flexible distal end to joint controls in the handle.

Final assembly of the catheter is performed 1055 by coupling the cannula with the handle and the flexible distal end portion.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments.

For example, the invention may be operated in an embodiment where a continuous insert is co-extruded over the transducer cable and then selectively etched or otherwise reduced in diameter to form full-size (unetched) inserts between these thinner (etched) sections. For example, material along the perimeter of the continuously extruded inserts and between thepull cable lumens 460 may be selectively removed, leaving only the transducer cables embedded in the remaining material between the unmodified inserts.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Reference signs in the claims, if any, shall not be construed as limiting the scope of the claims.

Claims (20)

1. An elongate medical device comprising:

a handle (110) comprising a steering element (115);

a flexible distal portion (130);

a cannula (120) disposed between the handle and the distal end;

wherein the distal end comprises a transducer (170);

at least one transducer cable (150), wherein the at least one transducer cable couples the handle to the transducer via the cannula; and

a plurality of articulation traction cables (160), wherein the plurality of articulation traction cables couple the steering element to the distal end via the cannula;

wherein the plurality of articulation cables are controlled at the steering element to articulate the distal end portion in a desired direction;

wherein the cannula comprises a plurality of inserts (400);

wherein the plurality of inserts are spaced apart along the cannula from the handle to the distal end;

wherein each insert of the plurality of inserts comprises a plurality of lumens (450, 460);

wherein the plurality of lumens comprises:

one or more transducer cable lumens (450) through which the at least one transducer cable extends, an

A plurality of pull cable lumens (460) through which the plurality of joint pull cables extend; and

wherein the plurality of lumens isolate the transducer cable and each of the plurality of joint distraction cables from one another.

2. The device of claim 1, wherein the flexible distal end is substantially more flexible than the cannula.

3. The apparatus of claim 1 or 2, wherein each of the one or more transducer cable lumens is disposed in a central region of each insert and each of the plurality of pull cable lumens is disposed along a peripheral region of each insert.

4. The device of any one of claims 1-3, wherein the pull cable lumen comprises a C-shaped lumen at a periphery of the insert.

5. The device of claim 4, wherein an opening (960) in the C-shaped lumen is smaller than a diameter of the joint distraction cable.

6. The apparatus of any one of claims 1 to 5, wherein the one or more transducer cable lumens are enclosed and fixedly attached to the one or more transducer cables.

7. The device of any one of claims 1 to 6, wherein each of the pull cable lumens is sized to allow each joint pull cable to freely travel through the pull cable lumen.

8. The device of any one of claims 1-7, wherein each of the plurality of pull cable lumens includes a lubricious material that facilitates advancement of the joint pull cable through the pull cable lumen.

9. The device of any one of claims 1 to 8, wherein each insert comprises a high temperature resilient material.

10. The device of any one of claims 1 to 9, wherein each insert is fixed to the cannula.

11. The device of any one of claims 1 to 10, wherein the at least one transducer cable, the plurality of joint distraction cables, and the plurality of inserts are arranged in a string (800) that is inserted into the cannula.

12. The device of any one of claims 1 to 11, wherein the device comprises a pull wire (850) fixedly attached to each of the inserts and enabling the plurality of inserts to be pulled into the cannula.

13. An assembly (800) of components, comprising:

a plurality of inserts (400) configured to be inserted into a cannula (120) of an elongate medical device;

one or more transducer cables (150) passing through each of the plurality of cards; and

a pull wire (850) fixedly attached to the plurality of inserts;

wherein each of the plurality of inserts includes a plurality of pull cable lumens (460) that enable a plurality of joint pull cables (160) to freely travel through each of the plurality of inserts.

14. The assembly of claim 13, wherein the assembly further comprises the plurality of joint traction cables.

15. The assembly of claim 13 or 14, wherein each insert comprises an elastic material and each pull cable lumen is C-shaped, each pull cable lumen comprising an opening (960) in the C-shape, the opening (960) being narrower than a diameter of the joint pull cable.

16. The assembly of any of claims 13 to 15, wherein each of the one or more transducer cables is fixedly attached to each insert.

17. A method of assembling an elongate medical device, comprising:

providing (10) a handle (110), a cannula (120), a flexible distal end (130), and a transducer (170);

forming (15-20) an assembly of components, the assembly comprising a plurality of inserts (400), one or more transducer cables (150) passing through each of the plurality of inserts; and a pull wire (850) fixedly attached to the plurality of inserts;

wherein each of the plurality of inserts includes a plurality of pull cable lumens (460);

passing (25) a plurality of joint distraction cables (160) through each of the plurality of inserts via the plurality of distraction cable lumens in each insert;

passing (30) the pull wire (30) through the cannula;

pulling (35) the pull wire to pull the assembly of components into the cannula;

attaching (50) the plurality of joint traction cables to a joint control device at the handle and to a termination at the distal end of the flexible portion;

coupling (45) the one or more transducer cables to the handle and the transducer at an end distal to the flexible distal end; and

coupling (55) the cannula to the handle and the flexible distal end.

18. The method as recited in claim 17, wherein the method includes attaching (40) the plurality of inserts to the cannula.

19. The method of claim 17 or 18, wherein the insert is elastic and each pull cable lumen is C-shaped with an opening (960) narrower than a diameter of the joint pull cable, and the method comprises expanding the opening with the elasticity of the insert, pressing the joint pull cable through the opening.

20. The method of any of claims 17-19, wherein the insert comprises a lubricious material that facilitates pulling the assembly of components into the cannula.

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